Kurds should be all moved back to Kurdistan, where they can be protected from Turkey.
There is no Kurdistan. That's a large part of the problem.
Erdogan didn't like the Kurds having a high degree of autonomy next to the border with Turkley's Kurdish lands. That's why he invaded. To separate the Syrian Kurds from his oppressed Kurds.
Let Syria-Russia fight Turkey over Syria.
Uh, we tried that under Obama. Result: millions of refugees which destabilized Europe. And the birth of a terrorist enclave run by ISIS.
US should never have been in Syria in the first place, backing the 'Muslim rebels' against the protector of the Christians Assad.
Obama tried to stay out, until ISIS filled the gap and gave a safe haven for terrorists.
It is curious that as the US found itself waging a global war against Muslim fundamentalists, it chose to overthrow Saddam's secular regime, undermine Assad's similar Baathist gov't, and bomb Qaddafi out of existence.
Also, dropped Mubarak like a rock and was willing to engage with the Muslim Brotherhood in Egypt.
All of which brought more power and influence to the religious gov'ts of Iran and Saudi Arabia. And the nascent Muslim nationalism of Turkey's Erdogan.
So the US has helped wipe out the ME secularists and allowed the religious fundamentalists to flourish.